Camera2: Compile with warnings, fix warnings

Change-Id: I557350abb32b0480f5da7dcecadfbe9edbe53361
diff --git a/services/camera/libcameraservice/CameraHardwareInterface.h b/services/camera/libcameraservice/CameraHardwareInterface.h
index 05ac9fa..167b37c 100644
--- a/services/camera/libcameraservice/CameraHardwareInterface.h
+++ b/services/camera/libcameraservice/CameraHardwareInterface.h
@@ -427,7 +427,7 @@
     /**
      * Dump state of the camera hardware
      */
-    status_t dump(int fd, const Vector<String16>& args) const
+    status_t dump(int fd, const Vector<String16>& /*args*/) const
     {
         ALOGV("%s(%s)", __FUNCTION__, mName.string());
         if (mDevice->ops->dump)
@@ -584,9 +584,10 @@
 #endif
 
     static int __lock_buffer(struct preview_stream_ops* w,
-                      buffer_handle_t* buffer)
+                      buffer_handle_t* /*buffer*/)
     {
         ANativeWindow *a = anw(w);
+        (void)a;
         return 0;
     }